Balance the Force
After logging 2k hours and over 2,500 podiums, mostly in tuning lobbies, I've learned a hard truth: chasing peak HP and slapping on ballast to fit a PP limit is a trap.
You need to prioritize grip, chassis balance, and a tuned transmission.
Especially in 700PP, you'll notice that the guys who are rockets on the straights are usually parking it in the corners or braking very early. GT7 tracks have significantly more corners than straights, which means one simple rule dictates the winner: The highest top speed does not win the race; the highest average speed does.
Dropping ballast weight and powerband sculpting (detuning for a broader torque curve) will win you more races than just throwing HP at the car and adding weight to counter the PP penalty.
Simply put: You might earn a 10 mph advantage on a track's 3 straights (+30), but you are bleeding 3 mph across its 12 different corners (-36). The lighter, balanced chassis takes the win nearly every time. It's a longer learning curve but prioritizing tuning for balance will yield some surprising results.